Basic knowledge of bronzing printing process in kraft paper bag packaging factory

Kraft paper bag packaging factories often use the process of bronzing when making packaging boxes. Everyone must be familiar with bronzing because it is a commonly used post-printing process, which can improve the grade of kraft paper bags. Various products Packaging boxes are designed with bronzing and are often used in various industries.

1. Hot stamping is to transfer the metal foil or pigment foil to the surface of the hot stamped product according to the graphic of the hot stamping template with the help of a certain pressure and temperature. The color of bronzing is not all golden, it depends on the color of the bronzing material. For example, the bronzing mentioned by the kraft paper bag packaging factory is generally yellow gold. For example, black, blue, and red are all acceptable.

2. There is more than one way of hot stamping, there are the following six common ones:

1. Gold foil stamping: good quality and high price

2. Silver foil hot stamping: good quality and high price

3. Copper foil hot stamping: powder foil, easy to oxidize and turn black

4. Aluminum foil hot stamping: flake, low price, easy to oxidize and turn black

5. Powder foil stamping: simple, poor quality

6. Anodized aluminum hot stamping: good quality, low price, no oxidation, multiple colors

Three, the main properties of anodized aluminum foil

1. Hot stamping temperature

The hot stamping temperature that can guarantee the quality of anodized aluminum during hot stamping is a range. Within a certain temperature range, the adhesive layer of anodized aluminum can be melted and bonded to the material to be adhered, and it will not be too hot due to excessive temperature. High and make the anodized aluminum lose its luster. This temperature range is generally between 70-130 degrees. The lower the lower limit temperature of the hot stamping temperature range, the easier it is to operate, and the equipment requirements are also high; the higher the upper line temperature, the more it can ensure that the anodized aluminum will not lose its luster and metal texture under the general hot stamping temperature. The wider the temperature range, the easier it is to operate, and the better the quality of hot stamping can be guaranteed. This temperature depends on the nature of the adhesive.

2. Bonding fastness

Refers to the firmness of the bonding between the anodized aluminum and the material to be stamped. It mainly depends on the bonding properties of the adhesive of the adhesive layer to the aluminum and the material to be stamped. Of course, it is also related to the hot stamping time, hot stamping temperature and hot stamping pressure. Adjusting the hot stamping process can improve the hot silver fastness of anodized aluminum.

3. Hot stamping quality

Whether the gloss of the anodized aluminum layer remains unchanged after hot stamping and whether the imprint is clear or not are very important properties of the anodized aluminum. The hot-stamped handwriting should be free of burrs, which is related to the adhesion of the release layer and the adhesive layer, and whether the coating is uniform or not.

4. Appearance quality

The surface of good anodized aluminum should be free of blooms, blisters, pleats and scribes, and the coating should be uniformly coated and curled evenly. Otherwise, the stamping quality will be affected.

Four, although the kraft paper bag packaging factory often uses the hot stamping process, but the hot stamping process is also widely used in other industries, such as hot stamping business cards, invitations, certificates, as well as plastic parts, toys, cosmetic packaging, leather bags and so on.